Sand-blast.



J. C. MYLES & H. GIRVIN.

' SAND BLAST.

APPLIOATION IILED NOV. 23, 1910.

1,038,781 v Patented Sept. 17, 1912.

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SAND BLAST.

APPLICATION FILED Nov. 23, 1910.

1,038,781., Patented sept. 17,1912.

2 SHEETS-SHEET 2.

UNITED STATES PATENT oEEio'E.

JAMES C. MYLES AND HAROLD GIRVIN, 0l? SAN IEIELANCISGO, CALIFORNIA.

i ,casser Specication of Letters Patent.

Application' filed November 23, 1910. Serial Ne. 593,807.

a sand blast embodying means operative to increase the eliiciency of the transmission of the sand and air to the place of operation; toA increase the 'height at which the sand and air may: be effectively used above the main sand tank; to p-rovide a horizontally disposed sand tank with means for automat-ically supplying sand to the tank while the apparatus is in use;.and principally to provide in combination with a sand containing4 tank one or more .mixing heads or guns especially 'designed to withstand the wear and to be conducive to the highest efiiciency in the mixing and discharging of sand and air.

The linvention consists of the parts, de.

tails of construction, and the combination of parts as more fully .hereinafter described in the accompanying drawings, in which- Figure 1. is aside view of the apparatus in partial sect-ion. Figa'2. is an end view of the apparatus. Fig. 3. is a central longitudinal section through the gun. Fig. 4. is a vertical central section of the same. Fig. 5. is a plan viewA of the tube connection.

In the present embodiment of our invention wev employ preferabl a 'horizontal cylindrical tank 2 supporte in any appropriate manner upon a skid 'or frame 3, and at they highest point and approximately midway its lengththere is connected to the tank a superposed supplementary hopper or tank, which in the present instance is shown as a. vertically disposed cylinder having a conical bottom 5 and between which andv 'the uppermost surface of the main sand tank 2 is interposed a suitable valve 6. The

auxiliary tank 4 is provided at its crown with a suitable trap or cover 7 which may be opened to allow sand to be charged in the auxiliary tank 4, and when closed is adapted to hermetically seal the chamber 4. By opening the valve v6 the .sand from the auxiliary tank 4 is allowed to flow in suitable .quantities into the horizontal main tank 2 in which it naturally andy automatically spreads or Hows to assume an ap- Patented Sept. 17, 1912.

proximately even surface which is exposed to 'the pressure of air led to the tank A through a suitable pipe or other connection 8 made with one of the end heads ot' tlc tank 2 adjacent the top of the tank.

The conductor 8 by which air under pressure is supplied to the tank 2 is connected at its end to what we term an auxiliary air head or chambert) which is provided with the pressure gage 10 and may bev connected as by a pipe 11 with any suitable source ot air supply not shown. lf desired a valve l2 vmay be mounted atany suitable point between the auxiliary air head 1() and the tank guns 15, Which we preferably make of hardened steel for the purpose of increasing their life and durability. Manifestly there may be as many of the discharge connections 13 and guns 15 as the Work in hand or the size of the apparatus may require, the

-sand flowing into the guns 15 through inclined ducts 1G, the lower ends of which communicate with the chambers 17 formed lin the front ends of the guns.

Forthe purpose of forcibly conveying the sand from the guns 15 and into suitable conveying tubes or pi es 18, the rear end of each of the guns is provided with the duct' 19 which are threaded for connections 2() with the auxiliary air head 9 and in which connections are interposed suitable 'controlling valves 21. By opening valves 21- air under pressure is conveyed through the connections 20 into the rear end chamber 19 of the guns 15, and the air is preferably reduced to small streams or jets by being 'forced through small erforat-ions 22 made through the center wal or diaphragm 23.

For the purpose of protecting the walls ot the chambers 17 of each of thel guns from wear to the greatest possible extent we have found that it is beneficial to make one of the holes 22, as the center one, substantially axial with the chamber 17 and to slightly incline the other holes 22 so thatl their axes will intersect at a point somewhat in front of the central orifice22. By this peculiar and special location the air 1n the chamber 19 passing through the jet openin picks up the sand in the chamber 17 an instead o thrusting it against the internal Walls of the chambers 17, tends to conver e the volume of sand centrally of the cham er by reason of the convergence of the several ducts 22, and thereafter the sand will be forced through the connvction 18 to the point of the discharge.

We `have found that the eiciency of the apparatus is greatly increased by convergthe place wherever it may be located, to the place of as much as a operation through two separate and distinct pipes, one for conveying air under pressure and one for conveying a volume of sand. We have found, by actual practice, that we are able to lift and apply sand, with the degree of force necessary, efficiently at main hopper sand tank 2.

During the' practical operation of the sand 'blastthe operator will open the valve 6 as sand is withdrawn from the main tank 2 and allow the same to be recharged from the upper tank 4. Having allowed the contents of the tank 4 to run into the main tank 2, the valve 6 is closed and the cover 7 may be opened and the new charge of sand .4, and when the valve height of 75 feet above the put into the auxiliary tank 4 and the cap 7 again closed hermetically sealing the tank 6 1s again opened the pressure of air inthe main tank and the auxiliary tank 4 will be equalized.

As before stated, the bottom of the filling tank is constructed in the shape of an inverted cone causing sand to flow freely to.

the center and completely enter the tank 2, thus avoiding` the accumulation of sand `which becomes `damp from the condensation of the compressed air.

Y Having thus described our invention, what we claim and desirelto secure by Letters- Patent, is-

1. A gun for sand blast apparatus having a mixing chamber, a sand passage having an inclined wall leading into said mixing chamber, an air chamber, and needle holes leading from said air chamber intov said mixing chamber through the inclined wall of the sand assage. y

2.- A gun or sand blast'apparatus having a mixingchamber, a sand passage substantially the diameter of said mixing chamber and being provided with an inclined wall, an air chamber, and needle holes leading from said air chamber to said mixing chamber through the inclined wall of sald sand passage, said needle holes being convergent and having their axesl intersectin at a point substantially coincident with the axis of said mixing chamber.

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

JAMES C. MYLES.

HAROLD GrIRVIN.`

Witnesses: Y

WiLLIAM K. GUrzxoir,

GEO. Pmreaas. 

